Table 2.

Cognitive accuracy: age by difficulty interaction.

Age group	Difficulty	Mean (%)	Standard error (%)	95% Confidence interval
				Lower bound	Upper bound
Younger	1-back	98.26	1.27	95.67	100.86
	2-back	89.74	3.35	82.90	96.57
Older	1-back	94.16	1.54	91.02	97.29
	2-back	75.94	4.05	67.68	84.20